Hitherto, many reports have been reported about transition metal complexes utilizable for organic synthesis reactions, for example, about catalysts being used for enantioselective synthesis reactions such as an enantioselective hydrogenation reaction, an enantioselective isomerization reaction, an enantioselective silylation reaction, etc. In these complexes, many of the complexes obtained by coordinating an optically active tertiary phosphine compound to transition metals such as rhodium, palladium, ruthenium, iridium, nickel, etc., have an excellent performance as a catalyst for an enantioselective synthesis reaction and for further increasing the performance of the catalysts, many phosphine compounds having specific structures have been developed as described, e.g., in Kagaku Sosetu (The Elements of Chemistry) 32, "Yuki Kinzoku Sakutai no Kagaku (Chemistry of Organometallic Complexes", 237-238(1982), edited by The Chemical Society of Japan.
In particular, 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (hereinafter referred to as "BINAP") is one of excellent ligands and a rhodium complex using BINAP as the ligand (JP-A-55-61937) (the term "JP-A" as used herein means an "unexamined published Japanese patent application") and a ruthenium complex using BINAP as the ligand (JP-A-61-63690) have already been reported. Also, it has also been reported that a rhodium complex using 2,2'-bis[di(p-tolyl)phosphino]-1,1'-binaphthyl (hereinafter referred to as "p-T-BINAP") as the ligand (JP-A-60-199898) and a ruthenium complex using p-T-BINAP as the ligand (JP-A-61-63690) give good results in an enantioselective hydrogenation reaction and an enantioselective isomerization reaction.
Furthermore, it has been reported that in an enantioselective hydrogenation reaction of nerol using as a catalyst a rhodium complex using 2,2'-bis(dicyclohexylphosphino)-1,1'-binaphthyl (hereinafter referred to as "CyBINAP"), citronellol having an optical purity of 66% ee was obtained [S. Inoue, et al., Chemistry Letters, 1007-1008(1985)].
As described above, for providing complexes having a higher performance as a catalyst for an enantioselective synthesis reaction, many specific phosphine compounds have been developed but according to the reactions and the substrates being used, these phosphine compounds are sometimes not yet sufficiently satisfactory in the point of the separation of the catalyst from the product formed and the reuse of the catalyst, and hence it has been desired to develop a complex which can be easily separated from the product formed as compared with conventional complexes (or catalysts).